Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 971
Filtrar
1.
Clin Med Res ; 22(3): 156-159, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39438149

RESUMO

Inferior vena cava (IVC) filters are commonly placed to prevent the development or worsening of pulmonary emboli. They are also inherently thrombogenic. Here we discuss a case of acute IVC filter thrombosis with the unusual presentation of obstructive shock resulting in death. A man, age 70 years, underwent laminectomy for multilevel spinal stenosis. An IVC filter was placed preoperatively for acute calf deep vein thrombosis (DVT). On postoperative day 4 he developed tachycardia, hypotension, and signs of lower extremity arterial insufficiency. No lower extremity swelling was noted. Imaging showed complete IVC occlusion caudal to the IVC filter with extension to bilateral iliofemoral veins. Arterial flow was preserved. Therapeutic heparinization was initiated and urgent percutaneous thrombectomy was performed. However, the patient developed multi-organ failure and died shortly thereafter. This report describes an uncommon etiology of obstructive shock and highlights a potentially life-threatening thrombotic complication associated with IVC filters that clinicians should be vigilant about.


Assuntos
Choque , Filtros de Veia Cava , Trombose Venosa , Humanos , Filtros de Veia Cava/efeitos adversos , Masculino , Idoso , Trombose Venosa/etiologia , Evolução Fatal , Choque/etiologia , Trombectomia/métodos , Trombose/etiologia , Trombose/diagnóstico
2.
Dokl Biol Sci ; 2024 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-39400891

RESUMO

The cranial and mandibular fragments of the medium-sized canid from the Early Pleistocene locality of Taurida cave (about 1.8-1.5 Ma) in Crimea are described and included in the hypodigm of the species Canis etruscus Forsyth Major, 1877, a common member of the Late Villafranchian fauna of the Circum-Mediterranean region. This species is reported for the first time from the Northern Black Sea region. The discovered evidence reinforce previous published idea regarding the periodically use of the Taurida cave by canids and other large predators as a den and shelter.

3.
Sci Rep ; 14(1): 20485, 2024 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-39227494

RESUMO

In recent years, the application of real scene 3D technology has become widespread in urban planning and cultural heritage protection. However, there has been relatively little attention paid to the construction of real scene 3D models for special natural landscapes such as caves. Given the global distribution of karst topography and the large number of naturally developed caves with diverse types, unique landscape styles, and significant scientific value, this paper enriches the research in this field. By combining ground-based and aerial remote sensing techniques, and based on 3D laser scanning and photogrammetry, we have successfully constructed a real scene 3D model of the internal structure of a karst cave with a precision better than 4 cm. Utilizing Unmanned Aerial Vehicle (UAV) oblique photography, we established a real scene 3D model of the external karst landform with a precision better than 2 cm. We also integrated the internal and external 3D models of the cave, developing a new, complete, and high-precision method for constructing real scene 3D models of karst cave landscapes. Furthermore, we proposed a method for texture reproduction in the dark environment inside the caves, enhancing the reproduction and visual appeal of the real interior. The establishment of high-precision real scene 3D models can not only serve as an effective tool for scientific research on caves but also, as replicas of the real world, play a crucial role in public dissemination and education, thereby enhancing public understanding of cave geological landscapes.

4.
Environ Microbiome ; 19(1): 67, 2024 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-39252078

RESUMO

BACKGROUND: Antibiotic resistance is a critical global concern, posing significant challenges to human health and medical treatments. Studying antibiotic resistance genes (ARGs) is essential not only in clinical settings but also in diverse environmental contexts. However, ARGs in unique environments such as anchialine caves, which connect both fresh and marine water, remain largely unexplored despite their intriguing ecological characteristics. RESULTS: We present the first study that comprehensively explores the occurrence and distribution of ARGs and mobile genetic elements (MGEs) within an anchialine cave. Utilizing metagenomic sequencing we uncovered a wide array of ARGs with the bacitracin resistance gene, bacA and multidrug resistance genes, being the most dominant. The cave's microbial community and associated resistome were significantly influenced by the salinity gradient. The discovery of novel ß-lactamase variants revealed the cave's potential as a reservoir for previously undetected resistance genes. ARGs in the cave demonstrated horizontal transfer potential via plasmids, unveiling ecological implications. CONCLUSIONS: These findings highlight the need for further exploration of the resistome in unique environments like anchialine caves. The interconnected dynamics of ARGs and MGEs within anchialine caves offer valuable insights into potential reservoirs and mechanisms of antibiotic resistance in natural ecosystems. This study not only advances our fundamental understanding but also highlights the need for a comprehensive approach to address antibiotic resistance in diverse ecological settings.

5.
Sci Rep ; 14(1): 20789, 2024 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-39242666

RESUMO

Permanent artificial lighting systems in tourist underground environments promote the proliferation of photoautotrophic biofilms, commonly referred to as lampenflora, on damp rock and sediment surfaces. These green-colored biofilms play a key role in the alteration of native community biodiversity and the irreversible deterioration of colonized substrates. Comprehensive chemical or physical treatments to sustainably remove and control lampenflora are still lacking. This study employs an integrated approach to explore the biodiversity, eco-physiology and molecular composition of lampenflora from the Pertosa-Auletta Cave, in Italy. Reflectance analysis showed that photoautotrophic biofilms are able to absorb the totality of the visible spectrum, reflecting only the near-infrared light. This phenomenon results from the production of secondary pigments and the adaptability of these organisms to different metabolic regimes. The biofilm structure mainly comprises filamentous organisms intertwined with the underlying mineral layer, which promote structural alterations of the rock layer due to the biochemical attack of both prokaryotes (mostly represented by Brasilonema angustatum) and eukaryotes (Ephemerum spinulosum and Pseudostichococcus monallantoides), composing the community. Regardless of the corrosion processes, secondary CaCO3 minerals are also found in the biological matrix, which are probably biologically mediated. These findings provide valuable information for the sustainable control of lampenflora.


Assuntos
Biofilmes , Cavernas , Biofilmes/crescimento & desenvolvimento , Cavernas/microbiologia , Biodiversidade , Itália , Bactérias/classificação
6.
J Environ Manage ; 370: 122285, 2024 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-39255577

RESUMO

A successful management of a show cave requires knowledge of cave dynamics and the main risk factors. Show caves close to the water table are prone to sporadic flooding, which can threaten visitor safety and result in severe economic losses. Las Güixas cave, located in the Collarada Massif (Pyrenees - Spain), is representative of a show cave close to the water table that is exposed to energetic flash floods. We conducted a five-year comprehensive cave monitoring study including air temperature, relative humidity, CO2 concentration and water level. Additionally, we measured outside temperature and precipitation. Air temperature variations and ventilation dynamics occurring in most of the cave are controlled by the outside temperature due to entrances at different elevations, except in a non-ventilated area showing more stable hygrothermal characteristics and higher summer values of CO2 concentration. The study also identifies distinct CO2 sources related to the degassing of water and visitors' breathing. Monitoring data show that the rapid degassing of cave water during flooding may increase subsurface CO2 concentrations to levels well above the exposure limits. However, the strong ventilation observed inside the cave rapidly removes CO2 peaks produced by flooding and limits the anthropic CO2 rise to ∼100 ppm. Hydrograph analysis revealed a response time of 8-12 h in the cave water levels to external rainfall/snowmelt events. Based on these results, a flood alarm system supports sustainable show cave management and the number of visitors is optimized according to the environmental conditions of the cave. This monitoring study has greatly contributed to our knowledge of cave dynamics, which can serve to improve flood risk management and increase the profitability of the show cave. Nonetheless, extreme floods remain a significant concern for potential economic losses in the future, considering current climate change scenarios. Hydrological studies together with a long-term monitoring will allow evaluating the impact of future changes in climate and environmental parameters.

7.
J Environ Radioact ; 280: 107540, 2024 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-39277991

RESUMO

This article presents the results of comprehensive radiological studies conducted in 2021 in order to assess the radiation situation in the Kungur Ice Cave (hereinafter referred to as the KIC). Since the cave is a fairly popular sightseeing object, therefore, the safety of both tourists and workers is a key task for scientific study. The radiation safety assessment was carried out taking into account the parameters of the radiation (gamma) background, measurements of radon and thoron concentrations, microclimatic indicators (air temperature, humidity), airflow rate, illumination and calculation of the indicator of a special assessment of working conditions (SAWC). Such comprehensive and detailed studies were conducted in the KIC for the first time, allowing some patterns to be identified and confirmed. For the indicators of gamma-activity and radon concentration, there is a clear dependence on the season of the year, which is directly related to microclimatic indicators, as well as to compliance with the ventilation regulations that have been established in the cave. The applied ventilation modes provide safe values of the radiation background and toron. In the summer months, the average radon content in the cave exceeds the maximum permissible concentrations by a factor of 7, which required calculation of the time of work in the cave. For the first time, special assessment of working conditions has been calculated for Kungur Ice Cave, but only for the winter period. The SAWC is defined for a working group consisting of engineers, workers and guides, taking into account such parameters as temperature, illumination, humidity, severity and intensity of labor and ionizing radiation (radiation background). According to preliminary data, the overall assessment of labor based on all parameters falls under the "harmful" class of conditions.

8.
Sci Total Environ ; 954: 176584, 2024 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-39349195

RESUMO

As a recurrent climatic phenomenon in the context of climate change, extreme rainstorms induce vertical translocation of organic matter and increase moisture content in terrestrial ecosystems. However, it remains unclear whether heavy rainstorms can impact microbial communities in the deep biosphere by modulating organic matter input. In this study, we present findings on the different responses of bacterial and fungal communities in a subsurface cave to rainstorms and moisture variations through field surveys and microcosm experiments. During periods of rainstorms, the influx of dissolved organic matter (DOM) from soil overlying the cave into cave sediments significantly enhanced the correlation between core bacteria and environmental factors, particularly fluorescence spectral indices. The resource utilization of core bacteria was diminished, while the functional diversity of core fungi remained relatively unaltered. We also performed simulated experiments with restricted external DOM inputs, in which DOM content was observed to decrease and microbial diversity increase in response to artificially increased moisture content (MC). The niche breadth of core bacteria decreased and became more closely associated with DOM as the MC increased, while the niche breadth of core fungi remained predominantly unchanged. Compared to fungi, cave bacteria exhibited higher sensitivity towards variations in DOM. The core microbiome can efficiently utilize the available organic matter and participate in nitrogen- and sulfur-related metabolic processes. The study systematically revealed distinct microbial responses to rainstorm events, thereby providing valuable insights for future investigations into energy utilization within deep biospheres.

9.
Zookeys ; 1211: 17-28, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39262609

RESUMO

This paper revises the genus Eurhaphidophora from China and describes a new species, i.e., Eurhaphidophoradulongjiangensis Zhu & Shi, sp. nov. The females of Eurhaphidophoratarasovidoitungensis Dawwrueng, Gorochov & Suwannapoom, 2020 and Eurhaphidophorafossa Lu, Huang & Bian, 2022 are described for the first time. Moreover, Eurhaphidophoracurvata Lu, Huang & Bian, 2022, syn. nov. is considered as a new synonym of Eurhaphidophorapawangkhananti Dawwrueng, Gorochov & Suwannapoom, 2020. Images illustrating the morphology of these species are provided.

10.
Trop Life Sci Res ; 35(1): 87-106, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-39262866

RESUMO

A cave represents a subterranean ecosystem that harbours a myriad of unique, peculiar, and secluded flora and fauna. These biotas have evolved with a wide range of ecological adaptations that allow them to thrive in harsh environments with limited light. Gua Kelam 1 constitutes part of the Gua Kelam limestone caves system in the Nakawan Range of Perlis State Park, Malaysia. Previous observations indicated that it harbours a plethora of spider species; however, their existence is still elusive as speleobiological studies remain unexplored. Herein, we identified the cavernicolous spiders found in the dark zone areas of Gua Kelam 1 through a complementary approach based on morphology and DNA barcoding. From the morphological analysis, we described three web-building spiders of JTKK2 and JTKK3 groups down to the species-level to belong to Nephilengys malabarensis, and Orsinome vethi except for Pholcus sp. from JTKK4 individuals. The molecular analysis of the cytochrome oxidase-I (COI) genes of JTKK2 and JTKK3 individuals showed that they exhibited a high degree similarity with N. malabarensis (98.3%), and O. vethi (100.0%), respectively except for JTKK4 individuals with only 91.4% homology with P. kuhapimuk. Phylogenetic analysis also generated a congruent tree, in which the identified species are well nested within the family Araneidae, Tetragnathidae, and Pholcidae. By this integral approach, the three spiders were determined as N. malabarensis, O. vethi, and Pholcus sp. These spiders are originally epigean in their habitat but uniquely thrive in Gua Kelam 1.

11.
Dokl Biol Sci ; 518(1): 234-238, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39212883

RESUMO

A mandible fragment of Acinonyx pardinensis (Croizet et Jobert, 1828) is described from the Early Pleistocene locality in the Taurida cave (Crimea, Late Villafranchian, about 1.8-1.5 Ma). This is the first discovery of the genus Acinonyx in the Pleistocene of Crimea. Along with other felids, such as Homotherium, Megantereon, Panthera, Lynx, and Puma, cheetahs were typical representatives of the Late Villafranchian faunas of Eurasia. In the Taurida locality, Acinonyx pardinensis is co-occurred with Homotherium crenatidens, Megantereon adroveri, and Lynx issiodorensis.


Assuntos
Acinonyx , Cavernas , Fósseis , Animais , Mandíbula/anatomia & histologia
12.
Microbiol Resour Announc ; 13(9): e0042624, 2024 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-39162447

RESUMO

Here we report the 16S rRNA gene amplicon analysis of the gut microbiota of three frugivorous cave bat species from the Cathedral Cave in Cavinti, Laguna, Philippines. Among the bat species, the most abundant phyla are Proteobacteria and Firmicutes D.

13.
Front Vet Sci ; 11: 1424890, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39091385

RESUMO

Introduction: Equine trigeminal-mediated headshaking is a painful neuropathic disorder comparable to trigeminal neuralgia in humans. The selective destruction of pain fibers within the trigeminal ganglion, called rhizotomy, is the surgical treatment of choice for idiopathic trigeminal neuralgia refractory to medical treatment in humans. The human trigeminal ganglion is enclosed by a dural recess called the Meckel's or trigeminal cave, in which the ganglion is surrounded by a cerebrospinal fluid (CSF)-filled subarachnoid space. During glycerol rhizotomy, glycerol is percutaneously injected in this CSF-filled space. Until now, information about the anatomy of the dural recess and the subarachnoid space surrounding the trigeminal ganglion is lacking in horses. The aim of this study was to explore if a CSF-filled subarachnoid space around the trigeminal ganglion exists in horses. Materials and methods: Six equine cadaver heads were investigated for CSF accumulation around the ganglion with a 3 Tesla MRI. After anatomical dissection to expose the trigeminal root, a polymer-based radiopaque contrast agent was injected through the porus trigeminus into the subarachnoid space (cisternography). The exact delineation and the volume of the contrast agent accumulation were determined on subsequent micro-computed tomographic scans and segmentation. Finally, the distribution of the contrast agent within the subarachnoid space was examined histologically in three specimens. Results: In all 12 specimens included in this study, the trigeminal ganglion was surrounded by a subarachnoid space forming a trigeminal cistern. The mean volume of the trigeminal cave in this study was 0.31 mL (±SD: 0.11 mL). Distribution of the contrast agent along the peripheral nerves (i.e., ophthalmic, maxillary and/or mandibular nerve) was observed in 7 out of 12 specimens. Discussion/conclusion: A subarachnoid space surrounding the trigeminal ganglion exists in the horse and could be targeted for glycerol rhizotomy in horses suffering from trigeminal-mediated headshaking. However, the clinical relevance of contrast agent distribution along the peripheral nerves remains to be assessed.

14.
Ecol Evol ; 14(8): e70157, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39130101

RESUMO

Riverine caves are special habitats that are home to many aquatic and terrestrial species. Some Odonata species and their emerging are recorded at the entrance and in the twilight zones of subterranean habitats around the world. However, the emergence of any Odonata species has not been recorded in the dark zones of caves or other subterranean habitats. We report the first evidence of the emerging of the Hyrcanian Goldenring, Cordulegaster vanbrinkae Lohmann, 1993, as an endemic species of the Hyrcanian biogeographical region, in the dark zone of Danial Cave, in the World Heritage-listed Hyrcanian Forests, northern Iran. During 2020-2023, three newly emerged and three exuviae of the species were recorded in the entrance zone (25 m) and the dark zone of the cave (200-280 m). The main hypothesis of the study is the entry and exit of adults from the cave entrance. However, we still do not know if the newly emerged will leave the cave or not. We still need more study on the biology and ecology of the species inside and around the cave. Danial Cave, with its high biodiversity, is one of the most important caves in the Middle East, and is urgently in need of conservation as a national natural monument.

15.
Ecol Evol ; 14(8): e11527, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39119175

RESUMO

Mites are among the most abundant invertebrates in subsurface ecosystems, and their community assemblages and distributions are often significantly influenced by the diversity of habitat resources. The cave ecosystem encompasses drastic changes in nonbiological factors, such as changes in lighting conditions from bright to extraordinarily dark and habitat gradients of surface plant resources from abundant to scarce or even disappearing, providing an ideal unique environment for evaluating the assembly mechanism of soil animal communities. Nevertheless, there still needs to be a sufficient understanding of the biodiversity patterns and drivers of mite communities across environmental gradients in karst caves. We conducted a comprehensive survey on the composition and diversity of soil mites in three photometric zones (dark, twilight, and light) of a typical karst cave and its adjoining extractive environments (forest scrub and farmland). Our research aimed to investigate the ecological relationships of mite communities between above- and below-ground habitats and the effects of abiotic factors on mite communities. We collected 49 families, 86 genera, and 1284 mites. In the external cave environment, we captured 1052 mites from 72 genera and 45 families; in the internal cave environment, we captured 232 mites from 46 genera and 29 families. The abundance, richness of genera, and diversity parameters of the mite community decreased from the cave entrance to the cave interior with decreasing light intensity. Oribatid mites dominated the mite community. Protoribates and Scheloribates were the dominant genera, along with Tectocepheus and 11 other genera, which primarily distinguished the mite communities among different habitats. Forty endemic taxa were found in the external cave environment, compared to 14 endemic taxa in the internal cave environment. The mite community showed a strong preference for the cave ecosystem habitat. Temperature, humidity, and soil nitrogen content significantly influenced the distribution pattern of mite communities (VIP > 0.8, p < 0.05).

16.
Asian J Neurosurg ; 19(3): 563-566, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39205907

RESUMO

Meckel's cave is a dural recess in the posteromedial portion of the middle cranial fossa, serving as a conduit for the trigeminal nerve and hosting various pathologies. The radiological diagnosis of Meckel's cave pathologies is often challenging, especially when they are atypical and rarely encountered. Here, we discuss the case of a 41-year-old woman who presented with right hemifacial pain, numbness, and binocular diplopia. Imaging features suggested a T2 hypointense, T1 hyperintense, and nonenhancing mass in the right Meckel's cave. Intraoperatively, an extra-axial black mass was observed, suggestive of melanoma, which was radically excised. Further postoperative workup and biopsy revealed it was a primary central nervous system (CNS) malignant melanoma, an exceedingly rare condition. Due to the rarity of the disease, a consensus regarding treatment regimens is lacking. This case report underscores the significance of considering uncommon diagnoses when faced with unusual radiological findings and emphasizes the importance of aggressive surgical resection and the evolving landscape of adjuvant treatments for primary CNS melanomas.

17.
Artigo em Inglês | MEDLINE | ID: mdl-39200573

RESUMO

Dimba Cave is a large array of natural galleries in limestone mountains of the Democratic Republic of the Congo that contains highly valued pre-historic archaeological artifacts. The cave attracts a high number of tourists every year and is used by local populations as a water supply source. The main objective of the research undertaken in Dimba Cave consisted of assessing the quality of water and sediments from Dimba Cave ponds through evaluating contamination by heavy metals (15 elements analyzed, including As, Cd, Pb, and Hg) and by microbial populations (including Escherichia coli and total coliforms) in order to estimate the ecotoxicological risk to humans and to non-human biota. All water samples collected in the cave ponds showed very high metal concentrations exceeding the internationally recommended limits for drinking water, particularly for Cr, Mn, As, Pb, and Hg. Most sediment samples from cave ponds also displayed high heavy metal concentrations. The calculated pollution parameters, such as the enrichment factor (EF), and ecological risk parameters, such as the ecological risk index (Eri), indicated that the sediment may be toxic to aquatic biota. Furthermore, the microbiological analysis of pond waters indicated a widespread contamination with bacteria such as Escherichia coli, Enterococcus spp., total coliforms, and Pseudomonas spp., probably from anthropogenic and/or animal sources. Therefore, the consumption of Dimba Cave water as a drinking water represents a threat to public health. Urgent management measures should be enforced to protect public health and the cave ecosystem.


Assuntos
Cavernas , Monitoramento Ambiental , Sedimentos Geológicos , Água Subterrânea , Metais Pesados , Poluentes Químicos da Água , República Democrática do Congo , Medição de Risco , Metais Pesados/análise , Metais Pesados/toxicidade , Sedimentos Geológicos/química , Sedimentos Geológicos/microbiologia , Sedimentos Geológicos/análise , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade , Água Subterrânea/química , Água Subterrânea/microbiologia , Microbiologia da Água , Escherichia coli/efeitos dos fármacos , Escherichia coli/isolamento & purificação , Humanos
18.
Chronobiol Int ; 41(8): 1199-1216, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39158061

RESUMO

In cave environments, stable conditions devoid of light-dark cycles and temperature fluctuations sustain circadian clock mechanisms across various species. However, species adapted to these conditions may exhibit disruption of circadian rhythm in locomotor activity. This study examines potential rhythm loss due to convergent evolution in five semi-aquatic troglobitic isopod species (Crustacea: Styloniscidae), focusing on its impact on locomotor activity. The hypothesis posits that these species display aperiodic locomotor activity patterns. Isopods were subjected to three treatments: constant red light (DD), constant light (LL), and light-dark cycles (LD 12:12), totaling 1656 h. Circadian rhythm analysis employed the Sokolove and Bushell periodogram chi-square test, Hurst coefficient calculation, intermediate stability (IS), and activity differences for each species. Predominantly, all species exhibited an infradian rhythm under DD and LL. There was synchronization of the locomotor rhythm in LD, likely as a result of masking. Three species displayed diurnal activity, while two exhibited nocturnal activity. The Hurst coefficient indicated rhythmic persistence, with LD showing higher variability. LD conditions demonstrated higher IS values, suggesting synchronized rhythms across species. Significant individual variations were observed within species across the three conditions. Contrary to the hypothesis, all species exhibited synchronization under light-dark conditions. Analyzing circadian activity provides insights into organism adaptation to non-cyclical environments, emphasizing the importance of exploring underlying mechanisms.


Assuntos
Cavernas , Ritmo Circadiano , Isópodes , Locomoção , Fotoperíodo , Animais , Ritmo Circadiano/fisiologia , Isópodes/fisiologia , Locomoção/fisiologia , Especificidade da Espécie , Luz , Atividade Motora/fisiologia , Comportamento Animal/fisiologia
19.
J Fish Biol ; 105(4): 1240-1255, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39082262

RESUMO

A new species of nemacheilid loach, Schistura sonarengaensis sp. nov., is described from three cave-dwelling populations (Barak-Surma-Meghna drainage) in the South Garo Hills district of Meghalaya, India. The new species possesses prominent eyes but is easily distinguished from all the congeners of the genus Schistura from Barak-Surma-Meghna and adjacent rivers drainages of northeast Indian (except S. syngkai) in having 13-26 vertically elongated to circular mid-lateral black blotches (brownish in life) overlayered on a grayish-black mid-lateral stripe on a dull white or pale-beige (golden brown in life) body. However, it can be easily distinguished from S. syngkai in having a complete (vs. incomplete) lateral line with more 72-89 (vs. 19-42) lateral-line pored scales, greater pre-dorsal length (48.5-53.1 vs. 41.9-44.1 %SL), a wider body at dorsal-fin origin (11.3-16.7 vs. 9.4-10.3 %SL), greater dorsal (18.1-21.1 vs. 15.1-17.0 %SL) and lateral (20.9-24.1 vs. 17.4-18.9 %SL) head length, a wider head (14.5-18.5 vs. 11.6-13.3 %SL), and moderately forked (vs. emarginated) caudal fin. Further, molecular analysis confirms the distinctiveness of S. sonarengaensis sp. nov. from its congeners found in northeast India by significant divergences with uncorrected genetic distance ranging from 3.7% to 17.3% in the mitochondrial cytochrome c oxidase subunit I (COI) gene dataset. The phylogenetic position of the new species with its sister species was evaluated using maximum likelihood and Bayesian analysis. The species delimitation approaches assemble species by automatic partitioning (ASAP) and Poisson tree processes (PTP) utilized for testing species assignments consistently identified our test group as a distinct species from its sister species. Although the new species lacks typical morphological adaptations usually associated with a subterranean life, such as complete absence (or vestigial presence) of eyes and pigmentation, it exhibits a reduction of pigmentation when compared to the epigean congeners.


Assuntos
Cavernas , Cipriniformes , Filogenia , Animais , Índia , Cipriniformes/anatomia & histologia , Cipriniformes/classificação , Cipriniformes/genética , Masculino , Feminino , DNA Mitocondrial/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética
20.
Front Microbiol ; 15: 1400700, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38993489

RESUMO

Stenotrophomonas maltophilia (S. maltophilia) is an emerging opportunistic pathogen that exhibits resistant to a majority of commonly used antibiotics. Phages have the potential to serve as an alternative treatment for S. maltophilia infections. In this study, a lytic phage, A1432, infecting S. maltophilia YCR3A-1, was isolated and characterized from a karst cave. Transmission electron microscopy revealed that phage A1432 possesses an icosahedral head and a shorter tail. Phage A1432 demonstrated a narrow host range, with an optimal multiplicity of infection of 0.1. The one-step growth curve indicated a latent time of 10 min, a lysis period of 90 min, a burst size of 43.2 plaque-forming units per cell. In vitro bacteriolytic activity test showed that phage A1432 was capable to inhibit the growth of S. maltophilia YCR3A-1 in an MOI-dependent manner after 2 h of co-culture. BLASTn analysis showed that phage A1432 genome shares the highest similarity (81.46%) with Xanthomonas phage Xoo-sp2 in the NCBI database, while the query coverage was only 37%. The phage contains double-stranded DNA with a genome length of 61,660 bp and a GC content of 61.92%. It is predicted to have 79 open reading frames and one tRNA, with no virulence or antibiotic resistance genes. Phylogenetic analysis using terminase large subunit and DNA polymerase indicated that phage A1432 clustered with members of the Bradleyvirinae subfamily but diverged into a distinct branch. Further phylogenetic comparison analysis using Average Nucleotide Identity, proteomic phylogenetic analysis, genomic network analysis confirmed that phage A1432 belongs to a novel genus within the Bradleyvirinae subfamily, Mesyanzhinovviridae family. Additionally, phylogenetic analysis of the so far isolated S. maltophilia phages revealed significant genetic diversity among these phages. The results of this research will contribute valuable information for further studies on their morphological and genetic diversity, will aid in elucidating the evolutionary mechanisms that give rise to them.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA